1. Field of the Invention
The present invention relates to a pavement cutter utilized in the road construction, repair and the like.
2. Brief Description of the Related Art
An asphalt cutter and a concrete cutter etc. are employed when pavement cuttings are required on road construction or repair sites. However, these cutters are only for straight and vertical cuttings. In these cutters rotating circular flat disks equipped with diamond blades etc. around their peripheries are used. Due to geometry (i.e. flat) of these cutters, naturally cut portions bear square shapes formed by straight cutting lines. In some cases, it is inevitable to cut excessively, as a result, to remove normal portions in order to remove deteriorated portions perfectly before the road repairing.
Some pavement cutters capable of circular cuttings are disclosed in the Japanese laid open patents. For example in the laid open No.7-279118 (Patent No.2528787) discloses a cutter with a trapezoidal cross section, almost spherical convex in its shape. The Japanese laid open utility model Nos. 62-159509 and 62-159510 disclose cutters having spherical convex cutting blades.
However, in the cutter disclosed in the laid open No.7-279118 where the cutting blade with trapezoidal cross section almost spherical convex is arranged, cutting friction against the pavement increases the more, the deeper the cutter penetrates into the pavement due to a geometry (trapezoidal cross section) of the cutting blade. In some cases cuttings of desired depth are impossible due to the increased friction.
Since cutters disclosed in the Japanese laid open utility models Nos. 62-159509 and 62-159510 with simple arrangements are for manual operations, they have drawbacks such as poor maneuverability and poor working efficiency from a practical point of view.
Since the above-mentioned conventional cutter are designed only for straight or circular cuttings, more tools and equipment, namely more transportation costs are required when two types of cuttings are necessary on sites.
In vertical cuttings, bonding strength between remaining portions and repaired portions tends to be weak. Sometimes repaired portions subside or collapse. (See FIG. 8B)
In view of the above-mentioned problems, the present invention is carried out to provide a pavement cutter to cut pavements into shapes for easy removing and to prevent repaired road from subsiding or collapsing. Since the road cutter according to the present invention is capable of cutting both straightly and circularly in accordance with situations, investment in the cutter is kept lower and saves transportation costs for the cutter. Further the present invention provides a cutter with good operating efficiency.
The cutter comprised as follows solve the above-mentioned problems.
(1) A pavement cutter equipped with a spherical shell disk for cutting pavement circularly by rotating a cutting blade arranged around a periphery of the spherical shell disk comprising; a base chassis equipped with front and rear wheel axes to which front and rear wheels are fixed movably and rotatably, a first tilting mechanism arranged on the front wheel axis as a base for said tilting mechanism where the base chassis is arranged so as to tilt around the rear wheels which play roles of supporting points without restraint,
a frame where a rotating axis to support the spherical shell disk and a driving unit are mounted, attached to one side of said base chassis via a hinge so as to move around an axis of said hinge, a second tilting mechanism to move the spherical shell disk downward having a cutting center determining means for setting a cutting radius so as to adjust the cutting radius flexibly before cutting operations and to move the spherical shell disk upward apart from the pavement for easy movements of the pavement cutter except during cutting operations.
(2) A pavement cutter equipped with a spherical shell disk or flat disk for cutting pavement circularly or straightly by rotating by a cutting blade arranged around the periphery of the spherical shell disk comprising; a base chassis equipped with front and rear wheel axes to which front and rear wheels are fixed movably and rotatably, a first tilting mechanism arrange on the front wheel axis as a base for the tilting mechanism where the base chassis is arranged so as to tilt around the rear wheels which play roles of supporting points without restraint,
a frame where a rotating axis to support the spherical shell disk and a driving unit are mounted, attached to one side of the base chassis via a hinge so as to move around an axis of said hinge, a second tilting mechanism to move the spherical shell disk downward having a cutting center determining means for setting a cutting radius so as to adjust said cutting radius flexibly before a cutting operation and to move the spherical shell disk upward apart from the pavement for easy movements of the pavement cutter except during cutting operations; wherein circular or straight cuttings are selected by exchanging from the spherical shell disk to flat disk and vice versa..
(3) The pavement cutter according to (1) or (2) wherein the arm fixed to the side face of the base chassis is arranged adjustably so as to adjust cutting radius during the circular pavement cutting.
(4) The pavement cutter according to (1) or (2) wherein an anchor is fixed to one side of the base chassis at a position where an extended axis of the hinge and an extended rotating axis of the cutting blade, an arm member to adjust a length of a sliding frame where the spherical shell disk or flat disk equipped with a rotating axis of the disk and a driving unit are mounted, is fitted to said hinge, so as to determine a cutting center of a desired cutting radius.
(5) The pavement cutter according to (1) or (2) wherein the spherical shell disk or flat disk arranged the cutting blade around the periphery of the disk has at least more than two perforations with desired sizes on desired positions except on said cutting blade for uniform cooling water supply and cooling.
(6) The pavement cutter according to (1) or (2) wherein a container for cooling water and nozzles are arranged on the base chassis so as to cool the spherical shell disk or flat disk equipped with the cutting blade by the cooling water via the nozzles.